Since the Industrial Revolution that began in the 18th century, various industries have developed. On earth, the amount of fossil fuels consumed has been increasing. This leads to a situation where discharged carbon dioxide gas remains up in the air and it exerts a role as greenhouse effect gas. On the ground, due to concrete buildings or asphalt roads, cooling actions on the ground have been degraded. For this reason, air-conditioners have been used more and more. As infrared rays due to radiation from concrete and asphalt are absorbed by air and clouds, it is difficult to release energy out of the earth. This results in a vicious cycle where an increase in the amount of fossil fuels used causes a further increase in greenhouse effect gas (for example, see Non Patent Literature 1). In a current situation, there are no definite technologies to decrease temperature of the ground and objects existing there.
Non Patent Literature 1: Yuki Ogawa, “Policy to prevent global warming”, Economic Policy Research, March 2006, No. 2, p.229 to 247